The browser based version of Improviz can be found at https://improviz-web.rumblesan.com/ and shares most of the functionality but with a few differences.
The code is available at https://github.com/rumblesan/improviz-web.
Currently there is no loading custom textures, geometries or materials. This will hopefully be added in the future, but for the time being there’s only what’s built in (and which probably needs to be expanded on).
There is also no way to send values to the program over OSC, though this too is on the roadmap.
The browser version has an integrated editor with built-in error notifications and code highlighting. It does support Vim bindings as well.
The sharing feature makes it possible to share Improviz programs (up to a size limit) by generating a URL from the program.